This invention relates generally to a device for the purifying treatment of a body of water and more particularly to such a device adapted to simultaneously aerate and chemically treat the body of water to prevent or retard eutrophication of the water.
Ponds, lakes and other bodies of water, particularly those in which water is generally quiescent, have a tendency to become eutrophic and thereby support dense growths of algae and undesirable underwater weeds that decay and deplete the water of oxygen. Without agitation, insufficient oxygen can be absorbed from the air by the water to replace that lost through eutrophication so that the water is unable to properly support fish and other aquatic life. The presence of excessive algae and certain types of weeds in lake waters is undesirable for various reasons, including the tendency of the algae to attract insects such as midges and the interference with navigation by thick weed growths.
Heretofore, numerous attempts have been made to aerate the waters of lakes, ponds and the like, but all such attempts of which I am aware have involved the use of shore-installed compressors and many feet of air line to convey compressed air from the compressors into the bodies of water being treated. Such systems have universally failed to do the job properly, primarily due to the fact that they result in the introduction of relatively large air bubbles into the water, which bubbles quickly rise to the surface and pass into the atmosphere. Only minute amounts of oxygen in the bubbles can be absorbed by the water during the quick rise of the bubbles to the surface. Consequently, very little aeration of the water can take place, and this only in the immediate vicinity of the vertically rising bubbles, which means that what little aeration does take place is localized, not uniformly occurent throughout the body of water, particularly where the body is relatively large as in the case of a big lake. Methods heretofore employed for the chemical treatment of bodies of water have generally involved the manual dumping of a treating chemical (typically copper sulfate) from a boat by a crew. Where a two man crew is employed for this purpose, the treatment of a good-sized lake can take several days, and sometimes even weeks.
As those skilled in the art will appreciate, the conventional methods and apparatus heretofore employed for the aeration and chemical treatment of large bodies of water have been time consuming and expensive, and, furthermore, have been largely ineffective in accomplishing the intended purpose with the desired degree of success.